From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/1918 Path: news.gmane.org!not-for-mail From: Galchin Vasili Newsgroups: gmane.science.mathematics.categories Subject: Category Theory and Hereditarily-Finite Sets Date: Wed, 18 Apr 2001 16:50:52 -0700 (PDT) Message-ID: <20010418235052.95337.qmail@web12205.mail.yahoo.com> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1241018203 1197 80.91.229.2 (29 Apr 2009 15:16:43 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:16:43 +0000 (UTC) To: categories@mta.ca Original-X-From: rrosebru@mta.ca Thu Apr 19 10:06:45 2001 -0300 Return-Path: Original-Received: (from Majordom@localhost) by mailserv.mta.ca (8.11.1/8.11.1) id f3JCRn509670 for categories-list; Thu, 19 Apr 2001 09:27:49 -0300 (ADT) X-Authentication-Warning: mailserv.mta.ca: Majordom set sender to cat-dist@mta.ca using -f Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 16 Original-Lines: 25 Xref: news.gmane.org gmane.science.mathematics.categories:1918 Archived-At: Hello Cat Theory Community, Hereditarily-finite sets are becoming increasingly more popular in computer science research. 1) What kind of interesting categories exist where an "object" is a hereditarily-finite set plus some structure on the set and a "morphism" would be a structure-preserving function. (I can think of the obvious subcategory of SET and also the category where an object is a hereditarily-finite set together with a "SET" endomorphism on that set, but neither of these categories would have interesting or useful properties, in my opinion) 2) What kind of papers can I read on this subject? Regards, Bill Halchin